package chapter04;
class Animal4{
    public void shout(){
        System.out.println("动物发出叫声");
    }
}
class Dog4 extends Animal{
    public void shout(){
        System.out.println("汪汪汪......");
    }
}
public class example4 {
    public static void main(String[] args) {
        Dog4 dog = new Dog4();
        dog.shout();
    }
}